The Besut river has its sources south of Jertih, in a valley with many tributaries, and surrounded by high hills. One of these tributaries has a well-known waterfall, Tembakah, but there are more, only known to the locals, as this area is very remote.
No signage, you need a guide, must ask around to find one. A good starting point for exploration is the La Hot Spring resort.
We found a guide in a coffee shop. He knew the way to a powerful fall, had been there decades(!) ago when they were logging the region. We decided to give it a try.

The La Hot Spring resort is a good base to start exploring

First you have to pass extended palm oil plantations

Then jungle trails follow

Where the Ulu Besut tar road comes to an end, you must first follow oil plantation roads, a 4WD would be handy. Next you follow clear jungle trails beside the river, until you can hear the waterfall. Scramble down and a beautiful waterfall is your reward.

Some river trekking

The impressive, powerful Belawan Fall

Notice how small the human figure is

Our guide tried in vain to find the upper fall, supposedly even taller. After giving up our search, we relaxed at the middle falls, more like cascades, just above the lower fall.

The middle falls

Our guide exploring

Notice the human!

You will notice that our guide was carrying a gun. We saw footprints that belonged to a "badak" according to him. A rhinoceros??